Over the years, sterilization of medical devices has become more important and difficult. At one time it was possible to sterilize most medical devices at the site of use, since the devices were relatively simple, such as reusable syringes, scalpels, scissors or the like. In addition, the medical devices were often used in a doctor's office, hospital, or the like, that included sophisticated sterilization equipment. Thus, the medical devices could be shipped for use without sterilization.
However, medical devices have changed considerably over the years. For instance, the devices are becoming more complicated and use many different materials, such that autoclaving, chemical sterilization, or the like, is no longer possible, since the processes would likely destroy the materials of the medical device or fail to reach areas not readily accessible after construction of the medical device. In addition, many medical devices are now being used in the home by patients, and these patients generally do not have the equipment necessary to perform the required sterilization. Thus, on-site sterilization has become difficult or impossible to perform at the site of use.
To overcome this drawback, most devices are now sterilized at the facility of manufacture, prior to shipment. Sterilization can be facilitated by sterilization of each component prior to assembly in a sterilized environment. However, additional sterilization is often required. Heat and chemical sterilization cannot always be used due to possible destruction of the various materials. To overcome issues of heat and chemical sterilization, radiation (including x-ray and electron beam) sterilization was developed to provide sterilization of a medical device once it was in its packaging. Thus, after sterilization, the device is shipped and stored in a sterilized environment until the medical device is to be used.
Although radiation sterilization has solved many sterilization issues, it is difficult to sterilize complicated devices containing electronic circuits, since the radiation has the capability to damage or destroy semiconductor circuit elements. One approach is to remove the circuits prior to sterilization, but this still raises issues of sterilization when the device is reassembled.